A 14-day warm-up that doesn't pretend to be a volume ladder

Most warm-up advice is a table: day one, 50 emails; day two, 100; day three, 200. The numbers look reassuringly precise. They also assume the only thing being measured is volume, when the thing that decides your fate is what recipients do with the mail.

A warm-up is a controlled test. You are asking a small group of real subscribers a simple question — do you want this? — before you ask it of everyone. Volume is the independent variable. Engagement and complaints are the result.

Before day one

• Authentication aligned. DKIM signing the From domain, SPF valid, DMARC published. A new domain has no reputation to spend on misconfiguration.
• One sending stream. Warm the domain you will actually send from, on the platform you will actually use. Switching providers mid-warm-up resets the test.
• A seed list. Addresses across Gmail, Outlook, Yahoo and a corporate filter. You are checking placement, not just delivery.
• A complaint baseline. Know your normal rate before you scale. Google's bulk sender guidance puts the spam-rate ceiling at 0.3% and warns from 0.1%; your own baseline may be lower, and lower is better.
• A rollback. If day four goes badly, you need to stop the send, not the whole programme.

Days 1–7: only the people who asked

Send to your most engaged cohort — subscribers who opened or clicked in the last 90 days, or the people who joined for this specific thing. Not a purchased list, not a scraped list, not "everyone we have".

Day 1: a plain, personal email. One link. No images, no campaign template, no clever subject. The goal is a normal human reply rate, because replies are the strongest engagement signal a new sender can earn.

Days 2–3: the same cohort, a slightly larger slice. Keep the content useful and the frequency sane. Watch bounces, complaints and placement at the seed list.

Days 4–7: add the 90–180 day engaged segment. Increase volume only if the previous day was clean: no complaint spike, no blocklist listing, seed delivery in the inbox.

What "clean" means is your call, written down in advance. A workable rule: pause if complaints exceed 0.1%, if hard bounces exceed 2%, if any seed lands in spam, or if a major blocklist lists the domain or IP.